The present invention relates to apparatus for the catalytic purification of the exhaust gases in internal combustion engines wherein a cylindrical catalyst body traversed by the gas in the axial direction, is arranged in the interior of a sheet metal housing and is shock-dampened by means of a resilient envelope provided at its circumference which also seals the body relative to an outer housing.
When using delicate ceramic envelope materials, for example, on aluminum silicate base, premature wear thereof will occur without special sealing of the envelope at its end face. Such wear is caused on the one hand by the exhaust gas pulsations and on the other hand by the corrosive attack of the exhaust gases on the free front surface of the envelope.
To avoid this disadvantage, it has been proposed in German Patent Publication P 25 15 732, corresponding to U.S. Patent application Ser. No. 674,224, to deflect the exhaust gases into the interior of the catalyst body by sheet metal rings fastened to the housing. Such a measure gives no protection against chemical corrosion.
The problem underlying the invention is to seal the space between the catalyst body and the housing in a manner which not only ensures the complete closure thereof but also serves to retain the catalyst body.